JP2015014237A - Ignition device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ignition device capable of simultaneously realizing improvement of robustness, suppression of electrode consumption, and power saving.SOLUTION: An ignition device includes an auxiliary power source 2 for increasing electric current flowing to a secondary winding 41 by executing discharge and stop from a booster circuit 1 in a superposed state to supply energy for keeping discharge after starting the discharge of an ignition plug 5 by opening and closing a switch element 3 for ignition, and the auxiliary power source 2 includes an auxiliary switch element 20 for switching the discharge and stop from the auxiliary power source 2, and a delay time calculating section 210 increasing and decreasing a delay time for delaying start of driving of the auxiliary switch element 20, and increasing and decreasing a discharge time Tdetermining an energy charging time from the auxiliary power source 2.

Description

  The present invention relates to an ignition device for igniting an internal combustion engine, and in particular, includes an auxiliary power source for maintaining a discharge by flowing a current in a superimposed manner by switching after the start of discharge and a drive frequency calculation unit for calculating a drive frequency. The present invention relates to an ignition device.

In a spark ignition type internal combustion engine, a spark is discharged to an ignition plug by an ignition device including an ignition coil, and the fuel introduced into the combustion chamber by the discharge is used for combustion.
In order to improve the combustion state of the internal combustion engine, a multiple discharge type ignition device has been proposed in which a discharge is generated in the spark plug a plurality of times within one combustion stroke.
In Patent Document 1, in addition to a normal induction discharge type ignition device, a DC-DC converter that injects ignition energy into the secondary side of the ignition coil, an operation stop unit that stops the operation of the DC-DC converter, There is disclosed an internal combustion engine ignition device provided with an operation stop canceling means for canceling the operation stop when an operation state of the engine is detected.

Japanese Utility Model Publication 2-24066

  However, in the conventional ignition device, it is necessary to use a high breakdown voltage element for the DC-DC converter provided on the secondary side of the ignition coil in order to maintain the discharge. Therefore, there is a problem in that the size of the apparatus is increased due to the need to improve the heat dissipation and the heat dissipation, and the reliability is reduced due to heat generation of the high voltage element.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an internal combustion engine ignition device that is excellent in mountability and high in reliability without using a high withstand voltage element.

The present invention (7, 7a, 7b) includes at least a DC power supply (10), a booster circuit (1) for boosting the power supply voltage of the DC power supply (10), and a primary connected to the booster circuit (1). An ignition coil (4) that generates a high secondary voltage (V2) in the secondary winding (41) by increasing or decreasing the current of the winding (40), and an ignition signal (IGt) that is transmitted according to the operating condition of the engine The ignition switching element (3) for switching between supply and interruption of the current to the primary winding (40) in accordance with the secondary winding (41) and the secondary switching element (2) from the secondary winding (41). An ignition plug (5) for generating a spark discharge in the combustion chamber of the internal combustion engine by application of a secondary voltage (V2), and for igniting the internal combustion engine, 3) After opening and closing the spark plug (5) by opening and closing, After a lapse of delay time (Td), in order to introduce energy to achieve only sustaining a predetermined discharge period (T _DC), said boosting circuit (1) discharge from the stop and the primary winding (40) An auxiliary power source (2) that increases the current flowing through the secondary winding (41) by superimposing at a connection point with the ignition switching element (3), and the auxiliary power source ( 2) an auxiliary opening / closing element (20) for switching stoppage of discharge from the auxiliary, an auxiliary opening / closing element drive circuit (21, 21a, 21b) for opening / closing the auxiliary opening / closing element (20), and the operating status of the internal combustion engine A delay time calculation unit (210) that starts driving the auxiliary opening / closing element (20) with a predetermined delay time (Td) from the fall of the ignition signal (IGt) according to an engine parameter (EPr) indicating 210a, 2 Characterized by comprising a 0b) and.

Specifically, the delay time calculation unit (210, 210a, 210b) includes an engine speed (Ne), an intake pressure (P _IN ), an accelerator opening (Th), a crank angle (CA), an engine water temperature (Tw). ), EGR rate, air-fuel ratio (A / F), primary voltage (V1) of ignition coil (4), primary current (I1), secondary voltage (V2), or selected from secondary current (I2) Depending on the operating condition of the internal combustion engine determined based on one or more engine parameters (EPr), the lower the rotational speed of the internal combustion engine or the lower the load on the internal combustion engine, the lower the load of the auxiliary element (20). The delay time (Td) for starting the opening / closing drive is lengthened, and the delay time for starting the opening / closing drive of the auxiliary opening / closing element (20) as the rotational speed of the internal combustion engine is higher or the load of the internal combustion engine is higher ( Td) is shortened.

Further, the lower the number of revolutions of the internal combustion engine or the lower the load on the internal combustion engine, the shorter the discharge period (T _DC ) for maintaining discharge by the opening / closing drive of the auxiliary element (20), and the rotation of the internal combustion engine. The higher the number or the higher the load on the internal combustion engine, the longer the discharge period (T _DC ) for maintaining the discharge by the opening / closing drive of the auxiliary opening / closing element (20).

According to the ignition device (7, 7a, 7b) of the present invention, the delay time calculation unit (210, 210a, 210b) causes an appropriate delay delay time (Td) and discharge period (in accordance with the operating state of the internal combustion engine). T _DC ) can be calculated to adjust the opening / closing timing of the auxiliary opening / closing element (20), and the energy supplied from the auxiliary power source (2) to the spark plug (5) can be increased or decreased. Therefore, it is possible to reliably maintain discharge and suppress stable waste while suppressing waste of input energy.

The block diagram which shows the outline | summary of the ignition device in the 1st Embodiment of this invention 1 is a time chart for explaining the operation of the ignition device of FIG. The time chart which shows the operation | movement of the ignition device of the structure which does not comprise the delay time calculating part which is a principal part of this invention shown as the comparative example 1. The flowchart which shows the control method applied to this invention Example of map for interpolating delay time Td from engine parameters An example of a map for interpolating discharge period T _DC from engine parameters Characteristics diagram of conventional ignition device showing problems in low-rotation and low-load operation state shown as Comparative Example 2 As Example 2, the characteristic figure which shows the effect of this invention in the operating condition of low rotation and low load Characteristics diagram of conventional ignition device showing problems in high rotation and high load operation state shown as Comparative Example 3 As Example 3, the characteristic figure which shows the effect of this invention in the operating condition of high rotation and high load The block diagram which shows the outline | summary of the ignition device in the 2nd Embodiment of this invention The block diagram which shows the outline | summary of the ignition device in the 3rd Embodiment of this invention.

With reference to FIG. 1, the outline | summary of the ignition device 7 in the 1st Embodiment of this invention is demonstrated.
The ignition device 7 of the present invention is provided for each cylinder of an internal combustion engine 8 (not shown), and generates spark discharge in the air-fuel mixture introduced into the combustion chamber to perform ignition.
The ignition device 7 includes a booster circuit 1, an auxiliary power source 2, an ignition switching element 3, an ignition coil 4, an ignition plug 5, and an electronic control device 6 (hereinafter referred to as ECU 6) provided outside. , Is composed of.

The booster circuit 1 includes an energy storage inductor 11 (hereinafter referred to as an inductor 11) connected to a power source 10, and a boost switch element 12 (hereinafter referred to as a booster) that switches supply and interruption of current to the inductor 11 at a predetermined cycle. And a capacitor 15 connected in parallel to the inductor 11, a first rectifier element 14 that rectifies current from the inductor 11 to the capacitor 15, and a primary winding 40 of the ignition coil 4. That is, a so-called flyback type booster circuit is formed.
As the DC power supply 10 (hereinafter referred to as the power supply 10), a vehicle-mounted battery, a known DC stabilized power supply obtained by converting the AC power supply using a regulator or the like is used, and a constant DC voltage such as 12V or 24V is supplied. .
In the present embodiment, an example in which a so-called flyback type booster circuit is used as the booster circuit 2 is shown, but the present invention is not limited to this, and a so-called chopper type booster circuit can also be used.

As the inductor 11, a coil with a core having a predetermined inductance (L0, for example, 5 to 50 μH) is used.
A power transistor such as a thyristor or IGBT (insulated gate bipolar transistor) is used for the boosting element 12.
A boosting element driving driver (hereinafter referred to as driver 13) is connected to the boosting element 12.

An ignition signal IGt is transmitted to the driver 13 from an engine control device 6 (hereinafter referred to as ECU 6) in accordance with the operating condition of the engine.
The driver 13 generates a drive pulse V _GE that switches between high and low at a predetermined cycle for a predetermined period at a predetermined timing in accordance with the ignition signal IGt.
A drive pulse V _GE is applied from the driver 13 to the gate G of the boosting element 12 to switch the boosting element 12 on and off.

As the capacitor 15, a capacitor having a predetermined capacitance (C, for example, 100 to 1000 μF) is used.
A diode is used for the rectifying element 14 to prevent a backflow of current from the capacitor 15 to the inductor 11.

When the booster element 12 is opened and closed by the driver 13 in accordance with the ignition signal IGt transmitted from the ECU 6, the electrical energy stored in the inductor 11 from the power supply 10 is charged in a superimposed manner on the capacitor 15, and the capacitor 15 is charged / discharged. The voltage Vdc is boosted to a voltage (for example, 50 V to several hundred V) higher than the power supply voltage.
The ignition coil 4 includes a primary winding 40 obtained by winding a coil wire material N1 times, a secondary winding 41 via N2 turns, a coil core 42, a diode 43, and the like.
The voltage of the power source 10 is applied to the primary winding 40 of the ignition coil 4, and the current flowing through the primary winding 40 is increased or decreased to obtain the secondary voltage V <b> 2 in the secondary winding 41. A high voltage (for example, -20 to -50 kV) determined by N1 is generated.

A power transistor PTr such as a MOS FET or an IGBT is used for the ignition switching element 3 (hereinafter referred to as the ignition element 3).
The ignition element 3 switches between supply and interruption of current to the primary winding 40 in accordance with an ignition signal IGt transmitted from the ECU 6 in accordance with the operating state of the engine.
When conduction to the primary winding 40 is interrupted by switching of the ignition element 3, the magnetic field changes rapidly, and an extremely high secondary voltage V2 is generated in the secondary winding 41 by electromagnetic induction, and the ignition plug 5 is applied.

The auxiliary power source 2 includes an auxiliary opening / closing element 20 (hereinafter referred to as the auxiliary element 20) interposed between the capacitor 15 and the primary winding 40, and an auxiliary opening / closing element that drives the auxiliary element 20. An element drive circuit 21 (hereinafter referred to as a driver 21) includes a second rectifier element 22, a power supply 10, an inductor 11, and a capacitor 15.
The driver 21 in this embodiment includes a delay time calculation unit 210 that is a main part of the present invention.

The delay time calculation unit 210 delays the driving start of the auxiliary element 20 from the end position (falling) of the ignition signal IGt according to the engine parameter EPr indicating the operating state of the internal combustion engine E / G by an interpolation method described later. It calculates a delay time Td and the discharge period _{T DC.}
The driver 21, the ignition signal IGt falling synchronization with the delay time Td and a timer for counting the discharge period T _DC is built.

The application of the secondary voltage V2 from the ignition coil 4, the discharge is started, after the predetermined delay time Td elapses calculated by the delay time calculating unit 210, a predetermined discharge period T _DC only, auxiliary element from the driver 21 A drive pulse V _GS for driving 20 is output.
Auxiliary power supply 2, by the opening and closing of the ignition switching element 3, after starting the discharge of the spark plug 5, after the lapse of a predetermined delay time Td, in order to introduce energy to achieve sustaining a predetermined discharge period T _DC The current flowing through the secondary winding 41 can be increased by superimposing and stopping the discharge from the booster circuit 1 at the connection point between the primary winding 40 and the ignition switching element 3.

In accordance with the opening / closing drive of the auxiliary element 20, the discharge energy from the auxiliary power supply 2 is input, and the discharge from the auxiliary power supply 2 and the stop are performed in a superimposed manner, so that the second current flowing in the secondary winding 41 is increased. The secondary current I2 can be increased.
For the auxiliary element 20, a power transistor having high responsiveness such as a MOSFET is used.
A diode is used for the second rectifying element 22 and rectifies the current supplied from the capacitor 15 to the primary winding 40.

As the engine parameter EPr, for example, one or more parameters selected from the engine speed Ne, the intake pressure P _IN , the accelerator opening degree Th, the crank angle CA, the engine water temperature Tw, the EGR rate, the air-fuel ratio A / F, and the like are used. It is done.
The engine parameter EPR, to grasp the operating conditions of the internal combustion engine, according to later-described map as a blow-off occurs can be prevented, the delay time Td and the discharge period T _DC energy is interpolated is turned.
In the present embodiment, an unillustrated operating condition check provided in the internal combustion engine 8 such as an engine rotation sensor, an intake pressure sensor, an accelerator opening meter, a crank angle sensor, an engine water temperature gauge, an EGR sensor, an A / F sensor, etc. The engine parameter EPr detected by the means 9 is shown to be indirectly transmitted to the frequency calculation section 210 via the ECU 6, but information from the driving condition confirmation means 9 is directly input to the delay time calculation section 210. You may comprise so that it may do. Further, the primary coil voltage V1 and current I1, which are highly correlated with the combustion state of the engine, and the secondary coil discharge voltage V2 and current I2 may be added to the parameters.

By switching between discharging and stopping from the capacitor 15 by the auxiliary element 20, current flows in the primary winding 40 and the current / voltage generated in the secondary winding 41 is enhanced, thereby suppressing blowout. it can.
At this time, after the discharge is started by the application of the secondary voltage V2 from the ignition coil 4 by the delay time calculation unit 210, the auxiliary power supply is delayed by an appropriate delay time Td according to the operation state of the internal combustion engine. It has been found that by inputting energy from 2, energy saving and more stable ignition can be realized.
In addition, since energy is input from the primary winding 40 of the ignition coil 4, energy can be input at a lower voltage than when input from the secondary winding 41 side.

The operation of the ignition device 7 of the present invention shown as Example 1 with reference to FIG. 2A has a configuration without the delay time calculation unit 210 which is the main part of the invention shown as Comparative Example 1 with reference to FIG. 2B. Explain the problem.
As shown in FIG. 2A (a), an ignition signal IGt is transmitted from the ECU 6. As shown in this figure (b), the boosting element 12 is repeatedly turned on and off in a predetermined cycle in synchronism with the rising of the ignition signal IGt. At the same time, as shown in this figure (c), the ignition element 3 is turned on. It becomes.

By opening / closing the step-up element 12, the capacitor 15 is charged with electric energy from the inductor 11, and the charge / discharge voltage Vdc gradually rises as shown in FIG.
In synchronism with the fall of the ignition signal IGt, the driving of the boosting element 12 is stopped, and at the same time, the ignition element 3 is also stopped.

At this time, a high secondary voltage V2 is generated on the secondary winding 41 side of the ignition coil 4 and applied to the spark plug 5 as shown in FIG.
By applying the secondary voltage V2, a discharge occurs between the electrodes of the spark plug 5, and an extremely large secondary current I2 flows instantaneously as shown in FIG.

At this time, in the conventional spark igniter, as shown by the alternate long and short dash line in Comparative Example 1 in this figure (h), the secondary current I2 quickly decreases, the discharge path between the electrodes is interrupted, and the secondary The current I2 stops flowing.
However, in the present invention, as shown in the figure (d), after elapse of the ignition signal IGt predetermined delay time from the fall of td, during a given discharge period T _DC, auxiliary device 20 is turned on, As shown in this figure (e), discharging from the capacitor 15 charged to a high voltage is started, and a large amount of energy is supplied from the auxiliary power supply 2 as shown in this figure (f).

As shown in FIG. 5F, the delay time Td is immediately before the secondary current I2 falls below the limit current _IREF that causes blowout.
As a result, the energy input at the initial stage of discharge can be suppressed, and the secondary current I2 can be reduced with a minimum amount of energy even in the late stage of discharge when it is difficult to maintain the input energy near the limit current. Since the blowout limit current I _REF or more can be maintained, the discharge path can be maintained and the ignitability can be improved.
Since the secondary current I2 is proportional to the amount of energy supplied from the auxiliary power source 2, it can be appropriately increased / decreased within a range where blowout does not occur depending on the engine conditions, and can be adjusted by map data described later.

Here, with reference to FIG. 2B, a problem when the delay time calculation unit 210 which is a main part of the present invention, which is shown as Comparative Example 1, is not used will be described.
The comparative example 1 does not include the delay time calculation unit 210, and is implemented in that energy is quickly supplied from the auxiliary power source 2 after the start of discharge according to the discharge period signal IGw transmitted from the ECU 6. Different from Example 1.

In Comparative Example 1, by a signal IGw, the secondary current I2, showing a case in which the energy charge well before below the blowout limit current I _REF.
In this case, it is possible to maintain the discharge as shown in FIG. 6 (i), but it has been found that excessive input energy exceeding the blow-off limit causes waste of input energy and acceleration of electrode consumption.

Here, with reference to FIG. 3, an example of the discharge control method of the ignition device 7 of the present invention will be described.
The control program can be stored in a control IC or the like constituting the driver 21.
In the activation determination step of step S100, it is determined whether or not the ignition signal IGt transmitted from the ECU 6 has risen in accordance with the operation status of the internal combustion engine 8.
If the ignition signal IGt is off, the determination is No, and step S100 is repeated until the rising of the ignition signal IGt is detected.
If the rising of the ignition signal IGt is detected, the determination becomes Yes, and the process proceeds to step S110.

In the ignition element driving process in step S110, the ignition element 3 is turned on.
At the same time, the process proceeds to the step of starting boosting element drive in step S120, and the opening / closing drive of the boosting element 12 is started.
In the ignition signal fall determination process in step S130, it is determined whether or not the ignition signal IGt has fallen.
Until the falling of the ignition signal IGt is detected, the determination is No and step S130 is repeated.

During that time, the booster element 12 is repeatedly opened and closed, and the booster capacitor 15 is charged.
If the fall of the ignition signal IGt is detected in step S130, the determination becomes Yes and the process proceeds to step S140.
In the ignition element stop process in step S140, the ignition element 3 is turned off.
At the same time, the process proceeds to the step 150 for stopping the boosting element, and the boosting element 12 is also turned off.
As a result, an abrupt change in the current flowing through the primary winding 40 of the ignition coil 4 occurs, a very high secondary voltage V2 is generated on the secondary winding 41 side by electromagnetic induction, and insulation between the electrodes of the spark plug 5 is prevented. It is destroyed and discharge begins.

Next, in the delay time determination step of step S160, it is determined whether or not the delay time Td that has started counting in synchronization with the fall of the ignition signal IGt has elapsed. Until the delay time Td elapses, the determination is No and step S160 is repeated. That is, the start of auxiliary energy input from the auxiliary power supply 2 is waited until the delay time Td elapses.
When the count of the delay time Td is increased, the determination is Yes and the process proceeds to step S170.
In the auxiliary element driving process in step S170, the drive signal _VGS is applied from the driver 12 to the auxiliary element 20, and the auxiliary element 20 is turned on.
While the auxiliary element 20 is on, energy for maintaining discharge is continuously supplied from the boosting capacitor 15.

Next, in the discharging period elapses the determination process of step S180, whether or not to start counting in synchronization with the fall of the ignition signal IGt discharge period T _DC is elapsed.
Until the discharge period _TDC elapses, the determination is No and step S180 is repeated.

When the discharge period _TDC is increased, the determination is Yes, and the process proceeds to step S190.
In the auxiliary element stopping step of step S190, the driving of the auxiliary element 20 is stopped and the input of energy from the auxiliary power source 2 is ended.
The delay time Td and the discharge period T _DC is interpolated to a value corresponding to the operating conditions by the interpolation method described below.

Figure 4A, with reference to FIG. 4B, described interpolation method of the delay time Td and the discharge period _{T DC.}
In order to interpolate the delay time Td, map data as shown in FIG. 4A is stored in the delay time calculation unit 210 or the ECU 6, and the length of the delay time Td is determined according to the operating condition of the internal combustion engine determined from the engine parameter EPr. And interpolated in the control flow described above.

For example, when the engine speed Ne is low and the intake pressure _PIN is also low, ignition is easy, so a value with a longer delay time Td is selected.
On the contrary, when the engine speed Ne is high and the intake pressure _PIN is also high, ignition is difficult, so a value with a short delay time Td is selected.
As a result, the energy input start time from the auxiliary power source 2 is delayed under the easily ignitable operating conditions, and the power consumption is suppressed, and the energy input from the auxiliary power source 2 is performed under the difficult ignitable operating conditions. The start time is accelerated, and the secondary current I2 is maintained.

Similarly, discharge period T _DC stores map data such as that shown in FIG. 4B to the delay time calculation unit 210 or ECU 6, in accordance with the operating condition of the internal combustion engine is determined from engine parameters EPR, the length of the discharging period T _DC Is determined and interpolated into the control flow described above.
For example, the engine speed Ne is low and the intake air pressure P _IN is low, because the ignition is easy, shorter discharge period T _DC value is selected.
On the contrary, high engine rotational speed Ne, when the intake air pressure P _IN is high, because the ignition is difficult, long discharge period T _DC value is selected.
As a result, the energy input period from the auxiliary power source 2 is shortened under the easily ignitable operating conditions, and the power consumption is suppressed. Under the difficult ignition conditions, the energy input period from the auxiliary power source 2 is achieved. And the secondary current I2 is maintained.

The engine operating status can also be determined from the engine speed Ne, the accelerator opening Th other than the intake pressure _PIN , the crank angle CA, the engine water temperature Tw, the EGR rate, the air-fuel ratio A / F, etc. in the case where it is determined that a high load is the discharge delay time Td shorter, the discharge period T _DC lengthened, when the low rotation, it is determined that low added is longer discharge delay time Td, the discharge period T _DC To shorten.
Further, the primary voltage V1, the primary current I1, the secondary voltage V2, and the secondary current I2 are directly read from the ignition coil 4, and if it is determined that it is difficult to maintain the discharge from the changes, the discharge delay time Td is set. short, by increasing the discharge period T _DC, it is also possible to achieve a stable ignition.

Here, with reference to FIG. 5A, FIG. 5B, FIG. 6A, and FIG. 6B, the test result which the present inventors conducted in order to confirm the effect of this invention is demonstrated.
FIG. 5A is a characteristic diagram showing a problem when ignition is performed under low-rotation and low-load operating conditions in a conventional ignition device not provided with the present invention as Comparative Example 2.
If the discharge path formed in the spark plug 5 is extended by the in-cylinder airflow flowing in the combustion chamber in the later stage of the discharge, the discharge voltage rises, the secondary current I2 is momentarily interrupted, and there is a risk of misfire.

On the other hand, when the ignition device of the present invention shown in FIG. 5B is used as an example 2 and the ignition is performed under the low rotation and low load operating conditions, the auxiliary power source 2 is used until the late discharge when the discharge is likely to blow out. Energy input from the auxiliary power source 2 is started after a predetermined delay time Td has elapsed.
With this configuration, energy is input from the auxiliary power source 2 at the later stage of discharge when blowout is likely to occur near the blowout limit current where blowout is likely to occur. Can be maintained.

FIG. 6A is a characteristic diagram showing a problem when ignition is performed under high rotation and high load operating conditions in a conventional ignition device not provided with the present invention, which is shown as Comparative Example 3.
In Comparative Example 3, blowout occurs earlier than Comparative Example 2 due to the strong in-cylinder airflow, the number of blowouts is large, energy consumption due to re-discharge is large, and the risk of misfire is further increased. .
FIG. 6B shows that when the ignition device of the present invention shown as Example 3 is used to ignite under high-rotation and high-load operating conditions, it is easy for the discharge to blow out early. The delay time Td for delaying the discharge is shortened, the discharge from the auxiliary power supply 2 is started early, and the discharge period _TDC is lengthened.

With such a configuration, it was confirmed that the rise of the secondary voltage V2 is suppressed, the discharge path is maintained, and stable ignition can be realized without causing the discharge path to blow out. The following knowledge was acquired by the above.
(1) The delay time Td from the fall of the ignition signal IGt to the start of opening / closing drive of the auxiliary element 20 as the rotational speed Ne of the internal combustion engine 8 or the load (intake pressure P _IN ) of the internal combustion engine 8 is lower. And the delay time Td until the opening / closing drive of the auxiliary opening / closing element 20 is started is shortened as the rotational speed Ne of the internal combustion engine 8 is increased or the load (intake pressure P _IN ) of the internal combustion engine 8 is increased. It is desirable to do.
(2) The lower the rotation speed Ne of the internal combustion engine 8, or, the lower the load of the internal combustion engine 8 (intake pressure PIN), the discharge period T _DC to achieve discharge maintained by opening and closing of the auxiliary element 20 is short, The higher the rotational speed Ne of the internal combustion engine 8 or the higher the load intake pressure PIN) of the internal combustion engine 8, the longer the discharge period (T _DC ) for maintaining discharge by the opening / closing drive of the auxiliary opening / closing element (20). Is desirable.
Note that the engine parameter EPr indicating the operating state of the internal combustion engine is not limited to the rotational speed Ne and the intake pressure _PIN . It can be appropriately selected from the above parameters.

With reference to FIG. 7, the ignition device 7a in the 2nd Embodiment of this invention is demonstrated. In addition, about the structure similar to the said embodiment, since the same code | symbol was attached | subjected and the branch number of the alphabet was attached | subjected to the different part, description is abbreviate | omitted about the same structure, and only a characteristic part is demonstrated.
In the above embodiment, the delay time calculation unit 210 is provided in the driver 21. Provided in the ECU 6 in the present embodiment, the result of calculation in the ECU 6, the delay time Td, in that the discharge period _{T DC} were to transmit to the overlapping manner driver 21a and the ignition signal IGt is different.
Also in the present embodiment, as in the above-described embodiment, energy can be input from the auxiliary power source 2 without excess or deficiency in accordance with the operation status of the internal combustion engine, thereby achieving both stable ignition and suppression of power consumption. be able to.

With reference to FIG. 8, the ignition device 7b in the 3rd Embodiment of this invention is demonstrated.
In the above embodiment, the data detected by the operating condition confirmation means 9 (not shown) provided in the internal combustion engine 8 such as an engine rotation sensor, an intake pressure sensor, an accelerator opening meter, a crank angle sensor, and an engine water temperature gauge are used as engine parameters. In the present embodiment, the primary voltage detection means 211 for detecting the primary voltage V1 of the ignition coil 4 is provided, the change of the secondary voltage V2 is predicted from the primary voltage V1, and this is delayed. The difference is that the delay time Td and the discharge time _TDC are calculated by feeding back to the time calculator 210b.
Also in this embodiment, the same effect as the above embodiment can be exhibited. Furthermore, a change in the secondary voltage may be predicted from the primary current, or the change may be predicted by measuring the secondary voltage V2 or the secondary current I2 and used for control.

7 Ignition Device 8 Internal Combustion Engine 9 Operating Condition Confirming Means 1 Booster Circuit 10 DC Power Supply 11 Energy Storage Inductor 12 Booster Switch Element (PTr12)
13 Boosting Open / Close Element Drive Driver 14 First Rectifier 15 Boosting Capacitor (C)
2 Auxiliary power supply 20 Auxiliary switching element (MOS20)
21 Auxiliary open / close element drive circuit (auxiliary driver)
210 Delay Time Calculation Unit 22 Second Rectifier Element 3 Ignition Open / Close Element (PTr3)
4 Ignition coil 41 Primary winding (L1)
42 Secondary winding (L2)
43 Core 44 Rectifier 5 Spark plug 6 Engine control unit (ECU)
IGt Ignition signal IGw Discharge period signal EPr Engine parameter Td Delay time T _DC discharge period V1 Primary voltage V2 Secondary voltage I2 Secondary current

Claims (7)

At least by the increase and decrease of the current of the DC power supply (10), the booster circuit (1) that boosts the power supply voltage of the DC power supply (10), and the primary winding (40) connected to the booster circuit (1). An ignition coil (4) that generates a high secondary voltage (V2) in the secondary winding (41), and an ignition signal (IGt) that is transmitted according to the operating condition of the engine, to the primary winding (40). An ignition switching element (3) for switching between supply and interruption of current and the secondary winding (41) are connected to the internal combustion engine by application of the secondary voltage (V2) from the secondary winding (41). An ignition plug (5) for generating a spark discharge in the combustion chamber, and igniting the internal combustion engine,
After the ignition plug (5) starts discharging by opening and closing the ignition switching element (3), the discharge from the booster circuit (1) is stopped and stopped after a predetermined delay time (Td) has elapsed. An auxiliary power source (2) that increases the current flowing through the secondary winding (41) by superimposing from the ignition switching element (3) side of the primary winding (40);
An auxiliary open / close element (20) for switching stoppage of discharge from the auxiliary power supply (2), an auxiliary open / close element drive circuit (21, 21a, 21b) for driving the open / close element (20) to open and close,
The driving of the auxiliary opening / closing element (20) is delayed by a predetermined delay time (Td) from the end position (falling) of the ignition signal (IGt) in accordance with the engine parameter (EPr) indicating the operating state of the internal combustion engine. And an ignition device (7, 7a, 7b) comprising a delay time calculation unit (210, 210a, 210b) to be started The delay time calculation unit (210, 210a, 210b) includes an engine speed (Ne), an intake pressure (P _IN ), an accelerator opening (Th), a crank angle (CA), an engine water temperature (Tw), an EGR rate, Air-fuel ratio (A / F), primary voltage (V1) of ignition coil (4), primary current (I1) of ignition coil (4), secondary voltage (V2) of ignition coil (4), ignition coil (4) Depending on the operating condition of the internal combustion engine determined based on one or more engine parameters (EPr) selected from any of the secondary currents (I2) of
The lower the rotational speed of the internal combustion engine or the lower the load on the internal combustion engine, the longer the delay time (Td) for starting the opening / closing drive of the auxiliary element (20),
The ignition according to claim 1, wherein the delay time (Td) for starting the opening / closing drive of the auxiliary opening / closing element (20) is shortened as the rotational speed of the internal combustion engine is higher or the load of the internal combustion engine is higher. Device (7, 7a, 7b) The lower the rotation speed of the internal combustion engine or the lower the load on the internal combustion engine, the shorter the discharge period (T _DC ) for maintaining discharge by opening and closing the auxiliary element (20), 3. The discharge period (T _DC ) for maintaining discharge by opening / closing drive of the auxiliary switching element (20) is lengthened as the rotational speed is higher or the load of the internal combustion engine is higher. Ignition device (7, 7a, 7b) Either the delay time calculation unit (210) or the engine control device (6) interpolates the delay time (Td) and the discharge period (T _DC ) from the operating state of the internal combustion engine determined from the engine parameters. The ignition device (7, 7a, 7b) according to any one of claims 1 to 3, wherein the ignition device (7, 7a, 7b) is stored as map data.   The energy input from the auxiliary power supply (3) is performed from a connection point between the primary winding (40) of the primary winding (40) and the ignition switching element (3). Ignition device according to any one of 1 to 4 (7, 7a, 7b)   The booster circuit (1) supplies and shuts off current to the inductor (11) for a predetermined period according to the energy storage inductor (11) connected to the DC power supply (10) and the ignition signal (IGt). A switching element (12) that switches between the inductor (11) and a capacitor (15) connected in parallel to the inductor (11), and a first rectifier that rectifies current from the inductor (11) to the capacitor (15) Ignition device (7, 7a, 7b) according to any of claims 1 to 5, comprising an element (14).   The auxiliary power source (2) is interposed between the capacitor (15) and the primary winding (40), and switches between the discharge and stop of the capacitor (15). A second rectifying element (22) for rectifying current from the capacitor (15) to the primary winding (40), the DC power supply (10), the inductor (11), and the capacitor (15) The ignition device (7, 7a, 7b) according to any one of claims 1 to 6,

Images